Artificial hand



' Jan. 10, 1950 R. B. TRAUTMAN 2,494,460

* ARTIFICIAL HAND Filed March 18, 1946 FIG. I

III

Patented Jan. 10, 1959 a ain UNITED STATES eTENT OFFlCE 3 Claims.

1 My invention relates to improvements in artificial hands and particularly to that type of appliance disclosed in Letters Patent of the United States, No. 1,362,156, granted to me December 14, 1920, for Artificial hand.

It has been found in practice that the artificial hand, patented as aforesaid, is particularly advantageous in respect to the feature whereby the thumb is locked closed with its tip in engagement with the tips of fingers of the hand. Said patented hand, however, has been somewhat 0bjectionable due to inadequate opening of the thumb which deprived the user from grasping relatively bulky objects and due, further, to the path followed by the thumb-tip in relation to the main portion of the hand whereby the user, when seated, was obliged unnaturally to present the hand, not fiatwise but more nearly endwise to the horizontal surface of a desk, table or the like in order to grasp an object thereon.

Broadly, it is a purpose of my present invention to overcome the above noted objections to my original invention, without sacrificing its thumb-locking feature or any of its other advantages.

More particularly, it is an object of my present invention to provide an artificial hand of the character indicated in which the thumb, though releasably locked closed upon the fingers, may be opened exceptionally wide by mechanism fully accommodated within the hand proper and opened so that the tip of the thumb is caused to travel in a relatively flat are generally paralleling the hand proper, whereby the wearer of the hand, seated at a desk, table or the like, can, in natural manner, present the hand substantially flatwise in respect to the horizontal surface thereof and swing the thumb under the hand readily to grasp an object resting on such surface.

Other objects of the invention reside in the novel combination and arrangement of parts and in the details of construction hereinafter illustrated and/or described.

In the drawings, Fig. 1 is a view illustrating an artificial hand from the back thereof, the same being an embodiment of the present invention and partially broken away to reveal otherwise concealed parts; Fig. 2 is a view of the appliance illustrated in Fig. 1 and showing the same from the thumb-side thereof with the thumb closed, said view being broken away to reveal parts within the hand proper for operating the thumb; Fig. 3 is a view similar to Fig. 2 showing the thumb in an open position.

Reference being had to the accompanying drawings, it will be seen that the artificial hand illustrated therein includes a main portion ID with rigid fingers H' thereon, the former having an elongated cavity l2 therein extending longitudinally thereof and opening at its palm-side. Two pintles i3, i4 mounted in the main portion III of the hand traverse the cavity l2 therein between the palm-side and the back thereof. The

first or foremost pintle l3 substantially parallels the back of said main portion l0 adjacent thereto and to the butts of the fingers I I. The second or rearmost pintle I4 is spaced rearwardly from said first pintle I3. I

Accommodated within the cavity 12 and swingably pivoted on the foremost pintle I3 is an arm i5 formed with a slot I6 therein extending lengthwise thereof. This arm l5 has a mounting branch i'i issuing sidewise therefrom and extending outwardly of the cavity I 2. The mounting branch I l is received within a kerf I8 formed in a thumb i9 and said thumb is riveted to said mounting branch.

The thumb l9 swings with the arm ['5 from an open position substantially at right angles to the main portion In of the hand to a closed position wherein the thumb-tip engages the tips of the first and second fingers ll. Said thumb (9 has a reduced butt portion 20 which is received within the cavity l2 and said butt portion 20 has a rearward extension 2! which closes the cavity 12 rearwardly of the thumb proper in the closed and partially closed positions of said thumb.

A lever 22, swingably pivoted on the rearm'ost pintle i 4, has a pin 23 issuing therefrom and slidably engaged in the slot Hi to provide a pin-andslot connection between said lever 22 and arm l5. This pin-and slot connection causes said arm !5 to swing in response to the swinging of the lever 22 and, in the closed position of the thumb is, said pin-and-slot connection further causes said arm l5 to be locked, in turn, to lock said thumb closed against forces applied there and tending to open the same.

A pull-cord 24 running through an opening 25 in the back of the main portion In of the hand yielding to the swinging of the lever 22 by the pull-cord 24, acts to reverse the throw of said lever and close the thumb 19 upon the slackening of said pull-cord.

In the cycle of movement of the thumb i9, the pin-and-slot connection between the arm 15 and lever 22 moves from a starting position adjacent the palm-side of the main portion Ill of the hand wherein the thumb is closed, then passes between the two -pintles l3, Hi arriving at a position ad- I jacent the back of said main portion In wherein the thumb is fully opened, and then retraces itself passing again between the pintles I3, Hi. When said pin-and-slot connection passes between said pintles l3, 14, upon its throw in either direction, the movement of the pin 23 along the slot It will be reversed. This reversal of movement of said pin 23 within said slot 5 provides a relatively wide-opening swing of the thumb l9 through a relatively short arm and a relatively pick up objects from or place them upon such surface with the hand disposed substantially fiat- "wise relative thereto.

This feature obviously dispenses with any necessity of unnaturally disposing the hand substantially on end with respect to the work surface to enable the thumb-tip to move into closed position along such surface.

Changes in the specific form of my invention, as herein described, may be made within the scope of what is claimed without departing from the spirit of my invention,

Having described my invention, what I claim as new and desire to protect by Letters Patent is:

1. .An artificial hand including a main portion and fingers thereon, the former having an elongated cavity therein extending longitudinally 1 "thereof and opening at its palm-side, a foremost pintle and a rearmost pintle in the main portion traversing the cavity therein between the palmside and the back thereof, an arm swingably pivoted on said foremost pintle and formed with a slot therein extending lengthwise thereof, a mounting branch issuing sidewise from said arm outwardly of said cavity, a thumb member secured to said mounting branch and swingable therewith from an open position substantially at 1 right angles to the main portion of the hand to a closed tip-"to-tip position in relation to the fingers, a lever swingably pivoted on said rearmost pintle, a pin on the lever slida'bly engaged in the slot in said arm and providing therewith a pin-and-slot connection for swinging the arm in response to the swinging of said lever and for locking said arm in. the closed position of the thumb, said connection :being movable back and tenth between the two pintles from a starting position adjacent the palm-side of said main pontion wherein the thumb :is locked closed to a position adjacentto the back of said main portion wherein the thumb is openly disposed, spring 4 means reacting against the lever for swinging the same in direction to close the thumb, a pull-cord attached to said lever for swinging the same in direction to open the thumb, said thumb having a rearward extension adapted to close the cavity rearwardly thereof in the closed position of said thumb, said extension being further adapted to engage said rearmost pintle to limit the opening throw of said thumb.

2. An artificial hand including a main portion and fingers thereon, the former having an elongated cavity therein extending longitudinally thereof and opening at its palm-side, a first pintle and a second pintle in the main portion traversing the cavity therein between the palmside and the back thereof, an arm swingably pivoted on said first pintle and formed with a slot therein, a mounting branch issuing from said arm outwardly of said cavity, a thumb member secured to said mounting branch and swingable therewith from an open position substantially at right angles to the main portion of the hand to a closed 'tip-to-tip position in relation to the fingers, a lever swingably pivoted on said second pintle, a pin on the lever slidably engaged in the slot in said arm and providing therewith a pin-and-slot connection for swinging the arm in response to the swinging of said lever, said connection being movable back and forth between the two pintles crosswise through the plane common to the axes thereof from a starting position adjacent the palm-side of said main portion wherein the thumb is closed to a position adjacent to the back of said main portion wherein the thumb is openly disposed, spring means reacting against the lever for swinging the same in direction to close the thumb, a pull-cord attached to said lever for swinging the same in direction to open the thumb, and means for limiting the opening throw of said thumb.

3. An artificial hand including a main portion "and fingers thereon, an arm and a lever both pivoted on said main portion and swingable on relatively spaced parallel pivotal axes, a pin-andslot connection between said arm and lever, a thumb mounted on the arm and swingable therewith back and forth from a closed tip-to-tip position in relation to the fingers to an open position substantially at right angles to the main portion of the hand, means for swinging the lever to effect such thumb-swinging movement of said arm through said pin-and-slot connection, said connection releasably locking the thumb in its closed position and movin to and fro crosswise through the space between said pivotal axes upon each cycle of said arm and lever in opening and closing said thumb, the pin "in said connection reversing its movement in the slot thereof upon the movement of said connection through said space in either direction.

' RAYMOND B.-TRAUTMAN REFERENCES CITED UNITED STATES PA'I'ENTS 'Name Date Trautman Dec. 14, 1920 Number 

